Straight bar knitting machines



Sept. 17, 1968 E. START ET AL 3,401,538

STRAIGHT BAR KNITTING MACHINES Filed Oct. 15, 1965 3 Sheets-Sheet 1 Sept. 17, 1968 E. START ET AL STRAIGHT BAR KNITTING MACHINES 3 Sheets-Sheet 2 Filed Oct. 15, 1965 Sept. 17, 1968 E. START ET AL 3,401,538

STRAIGHT BAR KNITTING MACHINES Filed Oct. 15, 1965 3 Sheets-Sheet 5 United States Patent 3,401,538 STRAIGHT BAR KNITTING MACHINES Ernest Start, Ruddington, and Leonard Brown, Nottingham, England, assignors to William Cotton Limited Filed Oct. 15, 1965, Ser. No. 505,105 Claims priority, application Great Britain, Oct. 21, 1964, 42,834/64 3 Claims. (CI. 6690) ABSTRACT OF THE DISCLOSURE A straight bar rib knitting machine, and method, for producing fabric with Milan stitch in a repeat three course sequence wherein cam operated frame and machine needles first form a rib course, a main cam shaft is shogged for a circular cam to render the machine needles inoperative while a plain course is formed on the cam operated frame needles, and cam operated propping out means for a cam follower lever renders the frame needles inoperative while a bar of yarn controlling elements, one to each frame needle, and having depending portions with downwardly projecting hooks, are cam introduced while the sinkers sink yarn about them, the sinkers are retracted and the elements are cam lowered to lower the yarn kinks onto the machine needles, the elements are cam advanced to push the yarn kinks under the machine needle beards, the machine needles and elements are advanced for pressing the machine needle boards, and the machine needles are retracted for knocking over the loops to form a plain course on the machine needles.

This invention is for improvements in or relating to straight bar rib knitting machines of the Cottons patent or similar type having two bars of co-operating needles usually vertical frame and horizontal machine needles.

The usual arrangement in this type of machine of feeding yarn to raised frame needles and onto advanced sinkers, which latter thereafter relinquish their yarn to the machine needles, precludes the machine fro-m making any fabric constructions where it is required for the machine needles to knit without the frame needles knitting.

In a particular fabric construction produced by what has been referred to as the Milan stitch, this has a three course sequence of (1) a rib course knitted on two series of needles, (2) a course of loops knitted on one of the two series of needles only, and (3) a course of loops knitted on the other series of needles only. This fabric has a limited degree of stretch and is advantageous for certain knitted garments.

An object of the invention is to provide mechanism in a straight bar rib knitting machine in such improved manner that the machine can produce Milan stitch fabric.

The invention provides a straight bar rib knitting machine having co-operating frame and machine needles, and in addition, having a bar of yarn controlling elements, with operating means for operating said bar of elements so that, with the frame needles lowered, said elements can substitute for the frame needles in receiving newly-fed yarn and relinquishing it to the machines needles, for the latter needles to knit without the frame needles knitting in required courses. Conveniently for producing Milan stitch fabric, the operating means is timed for operation of said bar of elements every third course following a first rib course formed on frame and machine needles, and a second course is formed on the frame needles only with the machine needles inoperative. Conveniently, also said elements operate above the machine needles and they have depending end portions about which new yarn is sunk by advancing sinkers, and the elements further have hooks projecting from the depending portions to catch the yarn in a lowering movement of the elements and to lower the yarn onto the machine needles which knit the yarn followed by raising of the elements to release them from the yarn.

The operating means for the bar of yarn-controlling elements conveniently comprises a cam operated mechanism for advance and retraction of the bar and further cam operated mechanism for raising and lowering the bar, with suitable control means to render the cam means operative for the third course of the sequence.

Prop means are operated to render the frame needles inoperative for the third course of the sequence, and usual means are provided for rendering the machine needles inoperative for the second course of the sequence.

The above and other features of the invention set out in the appended claims are incorporated in the construction which will now be described, as a specific embodiment with reference to the accompanying drawings in which:

FIGURE 1 is a cross sectional view of a Cottons patent straight bar rib knitting machine having yarn controlling elements according to the invention.

FIGURE 2 is a detail view of needles and associated elements at a yarn feeding stage.

FIGURE 3 is a similar detail view at a yarn-catching stage.

FIGURE 4 is a similar view at a machine needle advanced stage.

FIGURE 5 is a similar view at a machine needle beard pressing stage.

IGURE 6 is a similar view at a machine needle knock over stage.

FIGURE 7 is a similar view at a machine needle frame needle yarn feeding stage.

FIGURE 8 illustrates the fabric produced by the apparatus and method of the invention.

Referring to FIGURE 1 themachine has the usual frame needles 1 carried by the frame needle bar 2 which is operable for knitting by the usual mechanism including a cam follower lever 3 operable by the usual cam St: on the main cam shaft 13.

Similarly, the usual machine needles 4 are carried by machine needle bar 5 which is operable for knitting by the usual mechanism including arms 6 and a cam follower lever 6a operable by the usual cam 61) on the main cam shaft 13.

The usual sinkers 7 are operated by the usual mechanism.

In addition there is a bar 8 of yarn controlling elements 9 above the machine needle bar 5.

The elements 9 have depending end portions 9a from which project hooks 9b in the same direction in which the beards 1a of the frame needles 1 project.

The bar 8 is connected, for its advance and retraction, by link arms 10, 10a, 10b and link 100, to a cam follower lever 11 operable by a cam 12 on the main cam shaft 13 and, for raising and lowering, by link 14, lever 14a and link 14b to a cam follower lever 15 operable by a cam 16 on the main cam shaft 13. The link 14 interconnects the two members 10, 14a to corelate the two motions.

For the production of Milan stitch fabric there is required a three course sequence of knitting comprising l) a rib course of loops on frame and machine needles, (2) a course of loops on frame needles only and (3) a course of loops on machine needles only.

To provide for this sequence there is, in addition to the bar 8 of elements 9 and its operating mechanism, a prop lever 18 under control, through a connecting link 19 and cam follower levers 17, of a cam 17a on an auxiliary cam shaft 176, for propping out the cam follower lever 3 to retain the frame needles in lowered position for the third course of the sequence, and, for rendering the cams 12, 16 operative for the third course of the sequence, cam

follower rollers 11a, 15a of their respective cam follower levers 11, 15 are shiftable on their axles by shogging forks 11b, 15b on a spindle 11c, 150 which is connected by arm 11d, 15d and link He, 15:: to a control lever 11 15f engaging a control cam 11g, 15g on the auxiliary cam shaft 17b, the rollers being shifted onto the cams 12, 16 from circular cams.

For the second course of the sequence shogging of the main cam shaft 13 provides for retaining the machine needles inoperative, this causing a circular cam to engage the cam follower roller 60 of the cam follower lever 6a in place of the cam 6b. A typical shogging mechanism is disclosed in FIGURES 7 to 9 and corresponding description of British Patent No. 994,521, US. application No. 116,711 to which reference is directed for full details.

FIGURES 2 to 7 illustrate the operational steps for the third course of the sequence.

Starting at FIGURE 2 this shows the draw which is preceded by the frame needles 1 being lowered and there retained by the prop lever 18, and by advance of the bar 8 of elements 9 by the cam 12. This places the elements 9 in the positions normally occupied by the upper ends of the frame needles 1 when they are at their raised yarn feeding height. Consequently the new yarn Y is sunk by the normally advancing sinkers 7 about the depending portion 9a of the elements 9 to form yarn kinks K below the hooks 9b.

Next, FIGURE 3, the sinkers 7 are retracted in usual manner, and simultaneously the elements 9 are lowered by the cam 16 so that the yarn kinks K are engaged in the hooks 9b.

Lowering of the elements 9 continues during the usual advance of the machine needles 4 so that the hooks 9b draw the yarn kinks K down onto the machine needles 4, FIGURE 4.

The machine needles 4 proceed as usual to have their beards 4a closed by the presser 20, FIGURE 5, which is preceded by an advance motion of the elements 9 (by cam 12) to push the yarn kinks K under the machine needle beards 4a, so that the beards 4a press between the yarn kinks K and the old loops OL.

As the machine needles 4 are thereafter having their usual retracting knock-over motion, the elements 9 are raised by the cam 16 so that eventually, FIGURE 6, the old loops L are knocked over the yarn kinks K and the elements 9 are released from the yarn kinks K which then appears as a floating bar FB of yarn.

Thereafter in readiness for the next course, which will be a rib course, the elements 9 are returned by the cam -12, 16 to their inoperative position FIGURE 7, where they are retained consequent upon shifting the rollers 11a, 15a onto the aforesaid circular cams, and the prop 18 is released by the auxiliary cam shaft control of the link 19 so that the frame needles 1 are reintroduced to co-operate with the machine needles 4 in forming the rib course.

The next course will be thereafter formed by the frame needles 1 after simply rendering the machine needles 4 inoperative by the aforesaid shifting of the cam shaft 13.

It will be understood that there is one of the elements 9 substituting for each frame needle so that in the third course of the sequence formed by the steps of operation shown in FIGURES 2 to 7 there will be a series of the floating bars of thread FB crossing the frame needle wales of loops FNW as indicated at course 3c in the fabric view FIGURE 8. Similarly there will be a series of floating bars FBI of yarn formed in the second course 20 of the sequence and crossing the machine needle Wales of loops MNW as shown in FIGURE 8. The first course of the sequence is indicated at in FIGURE 8.

What we claim is:

1. In a straight bar rib knitting machine, a bar of frame needles, a first cam operated means for operating the frame needles to knit, a bar of machine needles, a

second cam operated means for operating the machine needles to knit, a row of sinkers, means for rendering the frame needles inoperative, a bar of rod-like elements one to each frame needle and each having a downwardly extending free end portion, downwardly projecting hooks on said portions of said elements, and a third cam operated means for imparting to said elements compound lowering, advancing, and return movements to cause said portions of said elements to receive yarn sunk by the sinkers, to next lower the sunk yarn onto the machine needles, to then push the sunk yarn under the machine needle beards, and thereafter to be raised clear of the sunk yarn.

2. In a straight bar rib knitting machine, for producing Milan stitch fabric in a three course sequence, in combination, a bar of frame needles and co-operating sinkers, a shoggable main cam shaft, frame needle cam operating means having a frame needle cam on said shaft and a frame needle cam follower lever, a bar of machine needles, and machine needle operating means having a machine needle cam on said shaft and a machine needle cam follower lever, operable for the first course of the sequence; and a first circular cam on said shaft for engagement by said machine needle cam follower by shogging the shaft to render the machine needles inoperative for the second course of the sequence; and a bar of yarn controlling elements above the machine needle bar and having depending end portions and hooks on said portions projecting downwardly, element advancing and retracting means having an element advancing and retracting cam on said shaft and a cam follower lever with movable roller, element raising and lowering means having an element raising and lowering cam on said shaft and cam follower with movable roller, second and third circular cams on said shaft, propping out means having cam shaft, a cam and a cam operated prop for propping out said frame needle cam follower lever to retain said frame needles in lowered position, and cam operated shifting means for moving said rollers from said second and third circular cams onto said element advancing, lowering and return cams for rendering said bar of elements operative, for the third course of the sequence.

3. In a method of producing Milan stitch fabric, by a straight bar rib knitting machine, the steps comprising repeating a three course sequence wherein the first course is formed by cam operating a row of frame needles and a row of machine needles and operating a row of sinkers to knit a rib course, the second course is formed by shogging a main cam shaft to cause a machine needle cam follower to engage a circular cam to render the machine needles inoperative and cam operating the frame needles to knit a plain course on the frame needles, and the third course is formed by cam operating a prop to prop out a frame needle cam follower lever to render the frame needles inoperative and introducing by cam operation a bar of yarn controlling elements, one to each frame needle, above the machine needle bar and which have depending end portions with downwardly projecting hooks, operating the sinkers to sink yarn about the elements, retracting the sinkers and cam operating the elements to lower the yarn kinks onto the machine needles, advancing the elements to push the yarn kinks under the machine needle beards, advancing the machine needles and the elements and pressing the machine needle beards, and retracting the machine needles to knock over the loops to knit a plain course on the machine needles.

References Cited FOREIGN PATENTS 631,374 12/1927 France.

MERVIN STEIN, Primary Examiner.

R. FELDBAUM, Assistant Examiner. 

